John F. Sowa wrote:
> Implications for computational uses of a UoM ontology:
>
> 1. Whatever system of ontology we propose should support multiple
> "microtheories" or whatever else one would like to call them.
>
> 2. Some of those microtheories might assume good old Newtonian
> mechanics, others might use relativity, others might use a
> nonrelativistic quantum mechanics, and others might use the
> latest and greatest theories anybody has proposed.
>
> 3. But all of them can use the same words and values for the
> basic units of measure.
>
>
Assuming that they all use the same definitions, or _equivalent_
definitions, for the words, yes. But there may well be a problem with
"mass" and its relationship to "energy", for example.
> 4. Those points imply that a microtheory for units of measure
> should *not* contain detailed axioms and definitions of the
> underlying physical principles and theories.
>
> 5. The detailed axioms and definitions should be contained in
> microtheories for whatever physical theories are assumed for
> any particular application.
>
>
As I said previously, and David Leal pointed out as well, the problem is
that many kinds of quantity are formally defined in terms of "underlying
physical principles and theories". So an ontology that defines such a
KoQ must necessarily express the formulation per the theory that was
used by the community that expressed it. And that means that terms for
individual 'kinds of quantity' have to have common meaning or be
relegated to microtheories. And that doesn't mean just the 'base
quantities' (length, mass, time, temperature, ...); it also means the
derived quantities (force, energy, velocity, pressure, sound intensity,
capacitance, ...). The problem is that in areas like subatomic physics,
superconductors, and nanomechanics, some of these concepts have
different physical models. (01)
Shall we agree to formulate more than one ontology, e.g.:
- a fundamental ontology of quantity and measurement concepts
- a "microtheory" for the SI System of units, including primitive base
units and formal definitions of derived units
- other microtheories for other systems, such as English measure,
apothecary measures, and so on
- microtheories for subatomic physics, etc.
? (02)
I'd like to get this discussion past philosophical principles and down
to guidelines for the actual project. This thread is ostensibly a
discussion of David Leal's strawman, but I cannot relate much of the
discussion to anything I see in that draft. David has done the first
bullet above. He hasn't done anything about the other bullets. So, are
we now discussing what the other bullets should be? Or are we concerned
about the definitions in David's draft? (03)
And can we please try to change the subject line when we change the
subject? One of the threads is 3D/4D, one of the threads is how units
relate to prevailing scientific thought (and thus the problem of
definition), one of the threads is whether to include currency, and I
have probably missed at least one. Maybe we need to give these
contributions Issue names and numbers, so that we can identify the
topics, know how to sort them for the wiki, and just possibly recognize
when we have reached some conclusion. (04)
-Ed (05)
--
Edward J. Barkmeyer Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263 FAX: +1 301-975-4694 (06)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (07)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/
Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx
Config/Unsubscribe: http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/
Shared Files: http://ontolog.cim3.net/file/work/UoM/
Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard (08)
|